### Recent Question/Assignment

A/Prof. M.Sek (2017)
NEM3101 Engineering Analysis and Modelling
PROJECT
MODELLING AND SIMULATION OF VIRTUAL EXPERIMENTS INVOLVING
VARIOUS TYPES OF EXCITATION FOR DETERMINING THE FREQUENCY
RESPONSE FUNCTION AND NATURAL FREQUENCIES OF AN MDOF SYSTEM FROM THE EXCITATION-RESPONSE DATA.
Weekly progress reports: electronic version by the end of each week (Sundays).
Final submissions: Electronic version of report by end of Week 11 (21 May 2017) Printed version of final report: at Week 12 lecture
Oral presentations and electronic version of slides: Week 12 Labs
Frequency Response Function (FRF) is an experimentally obtained estimate of the transfer function between various points on a structure. For continuous systems the experiment is often the only method of determining the frequency response and dynamic characteristics of a structure – magnitude and phase relationship between response and excitation.
The educational objective of the project is to enhance understanding and skills relating to
• modelling and simulation of behaviour of MDOF systems in a modern programming environment (Matlab® and Simulink® )
• using numerical models to simulate experiments in order to obtain realistic data for development of post-processing methodology prior to real experiments
• decision-making process of selecting data acquisition parameters
• handling large data sets
• application of the FFT and the frequency domain for characterisation of dynamic properties of structures and systems
In the project you must demonstrate your competency of acquisition of learning outcomes as listed in the Unit of Study Guide.
The MDOF system under investigation is shown in Figure 1 and the relevant data is listed in Table 1.
Figure 1: MDOF system under investigation.
Table 1: Parameters of MDOF system.
Mass
(kg) Viscous damping coefficient (N/(m/s)) Sti ffness coefficient (N/m)
m1 First digit of ID / 10 c1 80 k1 (your ID number)
m2 0.9 m1 c2 80 k2 0.9 k1
m3 0.8 m1 c3 80 k3 1.1 k1
c4 80 k4 0.7 k1
Experiment with various types of force excitation to determine FRFs and find natural frequencies of the system.
Team work is strongly encouraged but individual original submission by each student covering all aspects of the project is required.